### Universal Set

This is the set from which all the elements being examined are members. The universal set is denoted by the symbol **U**.

Example

Using set builder notation, where {x:..} means ‘the set of all x such that’,

If A = {0, 1, 2, 3, 4, 5, 6…}

Then U = {x: x≥ 0, x Є W}

That is, the universal set, U = W, the set of whole numbers.